PROJECT SUMMARY/ABSTRACT The proposed research will provide the first daily-level test of the Prototype Willingness Model (PWM), examining the effects of decision-making cognitions on high-risk alcohol use and related negative consequences using multi-burst ecological momentary assessment (EMA) across one year among adolescents and young adults aged 15-25. Based on literature focusing on developmentally appropriate health models for young adults, the PWM assumes that health-risk behaviors occur either when individuals have developed intentions to engage in a risk behavior (and these intentions vary as a function of attitudes and perceived injunctive norms) or through willingness to engage in risks (which varies as a function of perceived vulnerability to negative consequences, perceived descriptive norms, and prototypes). To improve the predictive utility of the PWM and to fully understand the relationships between cognitions in predicting high-risk drinking behavior from a PWM perspective, these associations should be examined close in time at the daily level (Aim 1), across a variety of risk-conducive situations (e.g., in contexts with presence of peer risk behavior, marijuana use, unexpected or expected locations, and in contexts with known or unknown people) (Aim 2), and across different individual characteristics (e.g., age, experience, and personality characteristics) (Aim 3). We will test these aims by recruiting a community sample of adolescents and young adults (N = 1,100), living in the greater Seattle metropolitan area, and utilizing multi-burst EMA data collection to assess information about the daily relations between drinking cognitions and alcohol use across three weekdays and three weekends per quarter for four quarters across one year. The proposed study is both significant and innovative in that it uses a lifespan perspective to evaluate the PWM in relation to high-risk drinking behavior both at the daily level and developmentally over time (i.e., age and experience as moderators), uses multi-burst EMA data collection to allow for greater insight into factors contributing to increased risk in-the moment to provide guidance to prevention and intervention work for young adult alcohol use. We will gain a theoretically-informed perspective to foster prevention and intervention strategies to target those at greatest risk at appropriate stages of the lifespan and help to determine the timing (e.g., improving young adults' ability to make healthier choices in moments when they may be at greater risk for engaging in risky behaviors) and type of intervention (e.g., focused on social reactance or reasoned pathways) that is most relevant toward individual's needs.